Thousands of women leave hospital each year just six hours after giving birth, prompting concerns that they are pushed out too soon because of bed and staff shortages.

As The Observer today launches its Better Birth Campaign for improved maternity services, the pressures on hospital maternity beds - and poor conditions within the wards themselves - are leading to many new mothers being discharged too quickly.

Experts are worried that it does not give women the chance to establish breastfeeding, and that they may still be exhausted and weak after a long labour. Under the present rules, women are free to leave hospital six hours after the birth if there are no complications.

Doctors say that many women would rather be at home, but are leaving early because wards are overcrowded and they cannot get the support they need. The number leaving as soon as possible is not known, but is thought to be just under 1 per cent of the 600,000 women giving birth each year.

The government's National Institute for Clinical Excellence (Nice) will shortly produce a set of recommendations on postnatal care, following an investigation that was launched last year. It is expected to call for greater checks before a mother is discharged, so that staff can be assured that she will receive proper care at home and that she knows how to care properly for the baby. Some within the Nice group would like to see a minimum time of 12 hours.

One member, speaking anonymously, said: 'There is a concern that the tide has gone too far in favour of early discharge, and that it may disadvantage the NHS, in that women could develop problems that then bring them back into hospital. It's also clear that it is much harder for people to establish breastfeeding if they don't get the encouragement from the staff.'

In some countries, early discharge is prohibited. In the United States a federal law stipulates that women must stay for at least 24 hours after a normal delivery, and three days after a caesarean.

The Observer 's Better Birth Campaign will highlight the problems surrounding childbirth and what needs to be done to improve the quality of care and support couples receive during and after birth.

Maggie Elliott, president of the Royal College of Midwives, spoke about the need to improve postnatal care, particularly because there are too few midwives currently on the wards to meet the standards of support parents expect. She said: 'We are sending women out much too early, and if they don't want to go six hours is too soon. One of the problems is establishing breast-feeding, which can take time. If you have good community care, then a midwife can come to your home and help you, but not all areas of Britain have that.'

Elliott said it was a particular problem in London, which had a rising birth rate but had lost maternity beds. 'If you have women waiting in the delivery suite to come down to the postnatal ward, and those beds are full, then it is preventing women in labour from coming in. You have to say, do you mind going home now? You have no option ... It is not so much about staffing, but the actual capacity of the hospitals that is the problem.'

Statistics show a steady fall in the number of maternity beds in Britain, from 12,521 in 1983-84 to 9,309 in 2003-04.

This is partly because many stand-alone maternity hospitals have merged with other hospitals. In 1983 a woman having her first child might be in hospital for up to five days after the birth. The average is now a day.

A Department of Health spokeswoman said: 'There is no reason why a woman who has had a normal birth should not go home as soon as she is ready, provided that her clinicians believe it is safe for her to do so.'